title: Upregulation of endocrine gland-derived vascular endothelial growth factor in papillary thyroid cancers displaying infiltrative patterns, lymph node metastases, and BRAF mutation.
abstract: BACKGROUND
  Endocrine gland-derived vascular endothelial growth factor (Prok1) and prokineticin 2 (Prok2) are involved in the organ-specific regulation of angiogenesis, which is a crucial step toward cancer progression in most tumors, including those of thyroid gland. The oncogene BRAF V600E mutation is associated with poor clinical outcome of papillary thyroid cancer (PTC) and can independently predict its recurrence.
  
  
  METHODS
  Our hypothesis was that Prok1 and Prok2 expression levels associated with BRAF mutations can be prognostic factors for PTC outcome. Prok1 and Prok2 were examined in PTC, a cell line derived from a human PTC (designated FB-2), euthyroid multinodular goiter (MNG), Graves' disease (GD), and contralateral normal thyroid (NT) tissues from PTC cases. We evaluated BRAF mutation and its relationship with Prok1 expression pattern in PTC.
  
  
  METHODS
  We studied Prok1 and Prok2 mRNAs by real-time polymerase chain reaction and BRAF mutation by mutant allele-specific polymerase chain reaction amplification. Formalin-fixed, paraffin-embedded blocks of PTC and NT were used for the immunohistochemical determination of Prok1 using anti-endocrine gland vascular endothelial growth factor primary antibody.
  
  
  RESULTS
  Prok1 and Prok2 transcripts were both present in thyroid tissues, and Prok1 was differentially expressed in PTC compared to MNG, GD, and NT. Prok1 mRNA levels were very low in NT and MNG and significantly higher in PTC, FB-2, and GD (p<0.05). Prok1 protein was almost undetectable in NT but was highly expressed in all PTC samples having an infiltrative pattern of growth and lymph node metastases ( p<0.05). Further, the expression of Prok1 in PTC was associated with 60% of the samples being positive for the BRAF mutation ( p<0.05).
  
  
  CONCLUSIONS
  We found that Prok1 is significantly increased in PTC, and its expression in PTC is related to BRAF mutation. These results suggest that Prok1 could be a new useful marker for thyroid cancer progression. Prok1 therefore could also be a potential target for novel therapeutic strategies, although the lack of functional data suggests caution against generalization of this assumption
authors.affiliation: Department of Clinical and Experimental Medicine and Surgery, Endocrine Unit, Second University of Naples, Naples, Italy. daniela.pasquali@unina2.it
authors.forename: Daniela
authors.initials: D
authors.lastname: Pasquali
authors.forename: Angela
authors.initials: A
authors.lastname: Santoro
authors.forename: Pantaleo
authors.initials: P
authors.lastname: Bufo
authors.forename: Giovanni
authors.initials: G
authors.lastname: Conzo
authors.forename: William J
authors.initials: WJ
authors.lastname: Deery
authors.forename: Andrea
authors.initials: A
authors.lastname: Renzullo
authors.forename: Giacomo
authors.initials: G
authors.lastname: Accardo
authors.forename: Valentina
authors.initials: V
authors.lastname: Sacco
authors.forename: Antonio
authors.initials: A
authors.lastname: Bellastella
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Pannone
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma; D002291:Carcinoma, Papillary / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002460:Cell Line; D045744:Cell Line, Tumor; D005260:Female; D005768:Gastrointestinal Hormones / Q000096:biosynthesis*; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009479:Neuropeptides / Q000096:biosynthesis; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D015854:Up-Regulation; D042662:Vascular Endothelial Growth Factor, Endocrine-Gland-Derived / Q000096:biosynthesis*
chemical_list: D005768:Gastrointestinal Hormones; D009479:Neuropeptides; C467610:PROK1 protein, human; C423608:PROK2 protein, human; D042662:Vascular Endothelial Growth Factor, Endocrine-Gland-Derived; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf